I cut my selvages into shorter strips for sewing onto adding machine tape---they seem to multiply too but it's worth it in the end.
Oh, and before you ask, the adding machine tape is to keep them going straight. When I get enough sewn onto 1 yd sections of tape then I'll cut them into strips, add other fabric on, and make a quilt with them. I didn't know why to use the adding machine tape until I started doing it.